From The Art and Popular Culture Encyclopedia

Circumstantial evidence is evidence in which an inference is required to connect it to a conclusion of fact. By contrast, direct evidence supports the truth of an assertion directly—i.e., without need for any additional evidence or the intervening inference.

On its own, it is the nature of circumstantial evidence for more than one explanation to still be possible. Inference from one piece of circumstantial evidence may not guarantee accuracy. Circumstantial evidence usually accumulates into a collection, so that the pieces then become corroborating evidence. Together, they may more strongly support one particular inference over another. An explanation involving circumstantial evidence becomes more valid as proof of a fact when the alternative explanations have been ruled out.

Circumstantial evidence allows a trier of fact to deduce a fact exists. In criminal law, the inference is made by the trier of facts in order to support the truth of assertion (of guilt or absence of guilt).

Testimony can be direct evidence or it can be circumstantial. If the witness claims they saw the crime take place, this is considered direct evidence. For instance, a witness testifying that the defendant stabbed the victim is direct evidence. By contrast, a witness who says that she saw the defendant enter a house, that she heard screaming, and that she saw the defendant leave with a bloody knife gives circumstantial evidence. It is the necessity for inference, and not the obviousness of a conclusion, that determines whether or not evidence is circumstantial.

Forensic evidence supplied by an expert witness is usually circumstantial evidence. A forensic scientist who testifies that ballistics proves the defendant’s firearm killed the victim gives circumstantial evidence from which the defendant’s guilt may be inferred. (Note that an inference of guilt could be incorrect if the person who actually fired the weapon was somebody else.)

On the other hand, the additional circumstantial evidence of the defendant's fingerprint on the trigger would dovetail with this piece to provide corroborating evidence.

The two areas in which circumstantial evidence is of most importance are civil and criminal cases where direct evidence is lacking.

Civil law

Circumstantial evidence is used in civil courts to establish or refute liability. It is usually the most common form of evidence, for example in product liability cases and road traffic accidents. Forensic analysis of skid marks can frequently allow a reconstruction of the accident. By measuring the length of such marks and using dynamic analysis of the car and road conditions at the time of the accident, it may be found that a driver underestimated his or her speed. Forensic science and forensic engineering are common as much in civil cases as in criminal.

Criminal Law

With obvious exceptions (immature, incompetent, or mentally ill individuals), most criminals try to avoid generating direct evidence. Hence the prosecution usually must resort to circumstantial evidence to prove the mens rea levels of "purposely" or "knowingly." The same goes for tortfeasors in tortlaw, if one needs to prove a high level of mens rea to obtain punitive damages.

One example of circumstantial evidence is the behavior of a person around the time of an alleged offense. If someone was charged with theft of money and was then seen in a shopping spree purchasing expensive items, the shopping spree might be circumstantial evidence of the individual's guilt.

Forensic evidence

Other examples of circumstantial evidence are fingerprint, blood analysis or DNA analysis of the evidence found at the scene of a crime. These types of evidence may strongly point to a certain conclusion when taken into consideration with other facts, but if not directly witnessed by someone when the crime was committed, they are still considered to be circumstantial in nature. However, when proved by expert witnesses, they are usually sufficient to decide a case especially in the absence of any direct evidence. Owing to the development in forensic methods, old undecided cases (or cold cases) are frequently resolved.

A popular misconception is that circumstantial evidence is less valid or less important than direct evidence. This is only partly true: direct evidence is popularly, but mistakenly, considered more powerful. Many successful criminal prosecutions rely largely or entirely on circumstantial evidence, and civil charges are frequently based on circumstantial or indirect evidence. Much of the evidence against convicted American bomber Timothy McVeigh was circumstantial, for example. Speaking about McVeigh's trial, University of Michigan law professor Robert Precht said, "Circumstantial evidence can be, and often is much more powerful than direct evidence". [1] The 2005 murder trial of Scott Peterson trial was another high-profile conviction based heavily on circumstantial evidence.

Indeed, the common metaphor for the strongest possible evidence in any case—the "smoking gun"—is an example of proof based on circumstantial evidence. Similarly, fingerprint evidence, videotapes, sound recordings, photographs, and many other examples of physical evidence that support the drawing of an inference, i.e., circumstantial evidence, are considered very strong possible evidence.

In practice, circumstantial evidence has an advantage over direct evidence in that it is more difficult to suppress or fabricate.Template:Citation needed Eyewitness testimony is notoriously inaccurate at times,Template:Citation needed and many persons have been convicted on the basis of perjured or otherwise mistaken testimony. Good strong circumstantial evidence can be a far more reliable basis on which to determine a verdict.Template:Citation needed Circumstantial evidence normally requires a witness, such as the police officer who found the evidence, or an expert who examined it, to lay the foundation for its admission. This witness, sometimes known as the sponsor or the authenticating witness, is giving direct (eye-witness) testimony, and could present credibility problems in the same way that any eye witness does.

However, there is sometimes more than one logical conclusion inferable from the same set of circumstances. In cases where one conclusion implies a defendant's guilt and another his innocence, the "benefit of the doubt" principle would apply. Indeed, if the circumstantial evidence suggests a possibility of innocence, the prosecution has the burden of disproving that possibility.